Downloaded the latest version and put it in a temp folder on my hard disk along with a copy of what's on my USB as I wanted to time different encryption options, both on the hard disk to get a feel for relative speed as well as on the USB itself.
Problem: The first time I ran YD it crashed immediately, something about asking Windows for abnormal termination or some such. Second time started OK.
Minor annoyance: put password in first field and hit Tab. Instead of going to the next password field, focus went to the Cancel button.
Problem: YD proceeded to encrypt things. Took about 4 minutes. When done it stated that had done 8992 files in "33 seconds", not the multiple minutes it actually took. Same sort of error happened on the decryption.
It then asked to delete the original files which I gave it permission to do. Took about a minute.
Problem: When done some, but not all, of the folders were not deleted. One of the folders contained read only files that were not deleted.
Problem: Running YD again to unencrypt failed as there were both an encrypted disk and unencrypted files present. I had to move YD and the disk image to a subfolder, decrypt and then move erything out one level.